Systems and methods for identity-based encryption and related cryptographic techniques
First Claim
1. A method for using identity-based encryption (IBE) to securely convey data over a communications network from a sender to a receiver, comprising:
- at the sender, forming an IBE public key using a time element;
at the sender, obtaining IBE system parameters;
at the sender, encrypting the data using the IBE public key and the IBE system parameters;
at the receiver, receiving the encrypted data from the sender;
at the receiver, obtaining an IBE private key that corresponds to the IBE public key; and
at the receiver, decrypting the encrypted data using the IBE private key.
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Accused Products
Abstract
A method and system for encrypting a first piece of information M to be sent by a sender [100] to a receiver [110] allows both sender and receiver to compute a secret message key using identity-based information and a bilinear map. In a one embodiment, the sender [100] computes an identity-based encryption key from an identifier ID associated with the receiver [110]. The identifier ID may include various types of information such as the receiver'"'"'s e-mail address, a receiver credential, a message identifier, or a date. The sender uses a bilinear map and the encryption key to compute a secret message key gIDr, which is then used to encrypt a message M, producing ciphertext V to be sent from the sender [100] to the receiver [110] together with an element rP. An identity-based decryption key dID is computed by a private key generator [120] based on the ID associated with the receiver and a secret master key s. After obtaining the private decryption key from the key generator [120], the receiver [110] uses it together with the element rP and the bilinear map to compute the secret message key gIDr, which is then used to decrypt V and recover the original message M. According to one embodiment, the bilinear map is based on a Weil pairing or a Tate pairing defined on a subgroup of an elliptic curve. Also described are several applications of the techniques, including key revocation, credential management, and return receipt notification.
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Citations
20 Claims
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1. A method for using identity-based encryption (IBE) to securely convey data over a communications network from a sender to a receiver, comprising:
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at the sender, forming an IBE public key using a time element;
at the sender, obtaining IBE system parameters;
at the sender, encrypting the data using the IBE public key and the IBE system parameters;
at the receiver, receiving the encrypted data from the sender;
at the receiver, obtaining an IBE private key that corresponds to the IBE public key; and
at the receiver, decrypting the encrypted data using the IBE private key. - View Dependent Claims (2, 3, 4, 5, 6)
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7. A method for using identity-based encryption (IBE) to securely convey data over a communications network from a sender to a receiver, wherein the receiver has a credential, comprising:
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at the sender, forming an IBE public key using the credential;
at the sender, obtaining IBE system parameters;
at the sender, encrypting the data using the IBE public key and the IBE system parameters;
at the receiver, receiving the encrypted data from the sender;
at the receiver, obtaining an IBE private key that corresponds to the IBE public key; and
at the receiver, decrypting the encrypted data using the IBE private key. - View Dependent Claims (8, 9, 10, 11, 12, 13, 14, 15)
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16. An identity-based cryptographic method comprising:
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at a first party, forming an identity-based public key using a time element;
at the first party, performing cryptographic operations using the identity-based public key;
at a second party, obtaining an identity-based private key corresponding to the identity-based public key; and
at the second party, performing cryptographic operations using the identity-based private key. - View Dependent Claims (17)
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18. An identity-based cryptographic method comprising:
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at a first party, forming an identity-based public key using a credential of a second party;
at the first party, performing cryptographic operations using the identity-based public key;
at a second party, obtaining an identity-based private key corresponding to the identity-based public key; and
at the second party, performing cryptographic operations using the identity-based private key. - View Dependent Claims (19, 20)
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Specification